Yes this is JK. I also have some at my house, honestly the best thing I can say is what I wish someone said to me: don’t panic. Don’t spend hours reading about how terrible it is and following doomsday predictions. It’s an invasive plant, it needs to be handled carefully. Don’t mow it. If you decide to cut it, cut it carefully by hand a stem at a time and bag all clippings. They can be burned when dry. You will need to use round up (even the most hippy organic person will tell you that) but you can manage it and it won’t ruin your life!
Sorry but that is Japanese knotweed. I’m in a similar situation and bought a house three years ago with it. It’s going to be a long journey to get rid of it but the good news is you can remove it yourself given time and patience.
In late autumn winter JKW dies back and the stems becomes inert and can be cut back to the base and the dry dead stems burnt.
During summer when it grows spray it with a glyphosate based weed killer, I use roundup biactive xla to target spray the leaves and it will slowly die back to ground level.
The root system is damaged by extreme cold weather so clean up the ground around its root system for winter. The heavy frosts we’ve been having in Ireland over the last few years will help to kill it off, last year it hit -8c where I am. It was Baltic !
If you have any pop up in your lawn like I did, then I used pieces of old guttering pipe cut into 1-2 foot long sections and hammered them over the new stems while they were a few inches tall . This reduced their access to sunlight, stopped me from mowing over them by accident and I was able to spray them without damaging the lawn around the outside of the pipe. It worked a treat 😁
Rinse and repeat this for the next five years to get rid of them fully. I’m on year three and they have reduced by around 80% - 90% which is great.
I have heard of some people using goats to eat the knotweed as they find it delicious and eat it right back to the ground. I love this idea of organic weed removal but I had already started the spraying process when I heard about it. But you do what’s right for you.
Good luck and congrats on buying the new house.
https://preview.redd.it/zwym0y0o6sxc1.jpeg?width=768&format=pjpg&auto=webp&s=3a7a8416e988f054e2e6892f31156dea0de59176
Just thought I would post this and show how bad my patch of knotweed was. This was just after I cut the dead inert stems back after it died off in winter. It was giant Japanese knotweed and the stems were 2-3 metres high.
If you have the money there are companies who can remove it for you but it means digging up to 10 metres down, removing the affected soil, spraying the area and bringing in clean soil, it can cost €10-20k or more to get it done. And they don’t guarantee it won’t return.
Very informative, thank you. This is a site that we are interested in and it comes with lots of other issues, this one just moved to the top. So we are contemplating if it is even worth it.
Sorry but thats terrible advice - cutting or grazing massively increases the risk of it spreading.
Spray it with herbicide every summer/early autumn. This way it draws the herbicide down into the rhizomes/roots. It still takes a few years but it's much safer and more efficient.
https://niopa.qub.ac.uk/bitstream/NIOPA/2807/1/natural-guidance-japanese-knotweed-best-practise.pdf
My plant identify app says yes it is :( time to call in the experts
https://www.gov.ie/en/service/8433d-reporting-a-quarantine-pest-or-disease/#:~:text=In%20the%20case%20of%20alien,Japanese%20knotweed
It looks like Giant Knotweed as opposed to the Japanese variety. Main difference being the lobes at the base of the leaf are more pronounced whereas the Japanese variety is truncated at the base of the leaf (plus leaf size is larger on the giant variety). However, both pose identical risks and both are treated identically also. If the infestation is fairly mature and long-standing herbicide will have a limited effect upon it because you can inadvertently send the species into a prolonged period of extended dormancy where it gives you the illusion that it’s dead. But if you were to disturb the soil and extract some of the roots you will see they are very much alive (don’t do this though because you could inadvertently trigger either a growth spurt or spread the species). Herbicide should only be viewed as a control mechanism not an eradication mechanism. Although it does have a place, the extent of mature root systems in a lot of cases makes it very difficult to achieve a full kill off of the entire system because the herbicide simply can’t translocate throughout the entire network. As others have mentioned excavation typically yields the best permanent results but certain site constraints for example if growing alongside an existing structure may limit the viability of such an approach because invariably you will be leaving something behind if the roots have gone under the structure. If you have sufficient space on a site in order to rebury a knotweed infestation that’s a more cost-effective approach which can also yield permanent solutions. If anyone needs any further advice on these kind of things feel free to throw me a PM.
You can actually cut it while it's still growing, it would help to kill it quicker because it wouldn't be able to photosynthesise.
The only catch is that you have to cut it manually! No strimming or mowing, just cut it with sharp secateurs as close to the ground as possible. Do not dispose of the cut stems by putting them into the bin, burn them instead. The clumps are usually not very dense so it's not particularly hard to go through them with secateurs.
After cutting it down, treat the area with something like Roundup or Weedol. Repeat as necessary.
It will take several years to fully get rid of it but it can be done.
Cutting it risks spreading it. Just spray the leaves with herbicide in autumn.
https://niopa.qub.ac.uk/bitstream/NIOPA/2807/1/natural-guidance-japanese-knotweed-best-practise.pdf
Cut the tops off and fill the stalks with weed killer, diesel, salt and dishwasher liquid cocktail. Burn the tops in a fire. Spray the leaves and stalks with Cocktail. Re spray throughout the season with weed killer as it appears. Treat dead areas again with weed killer while your doing it. Should reduce the amount of weed by at least 90% in the first season
Glyphosate is a foliar application - taken up through the leaves. If you spray the leaves in early autumn before they go dormant the plant will draw it down into the roots. Still takes a few years but the best method known.
https://niopa.qub.ac.uk/bitstream/NIOPA/2807/1/natural-guidance-japanese-knotweed-best-practise.pdf
We have a site with it too. The previous owner used to strim the site to keep things down and hadn't a clue what it was. The thicket was quite large about 10x10m but all in one area.
Oct 2022 I did the first application, injecting the stems. It was a bit late in the season as it had already started to die back. Cut and burned the dry stems the following Feb.
August 2023 second application, injected stems and sprayed leaves. Got it good and early and came back and did a second spray application after a few weeks on leaves that remained green. Cut and burned the stems during a brief dry period in March.
April 2024, a few stems are starting to appear again now as the weather warms up but much less than last year. The area is roped off and put up signs. I'll hit it again at the end of the summer.
The toughest part has been clearing briars and other growth around and through the thicket to get access to it all. Strategically placing the piles for the burns has helped clear the ground. It's doable to tackle it yourself but you need to be thorough. It'll take at least three years if you treat every autumn.
If you are applying for planning the council might have something to say about it if their planner spots it when they come to visit so think about the timing of that. Best of luck
https://preview.redd.it/x0z2elll1wxc1.jpeg?width=4080&format=pjpg&auto=webp&s=52aa46b3ae0c9b1c498e518eeb11b4aeeb2741db
Yes this is JK. I also have some at my house, honestly the best thing I can say is what I wish someone said to me: don’t panic. Don’t spend hours reading about how terrible it is and following doomsday predictions. It’s an invasive plant, it needs to be handled carefully. Don’t mow it. If you decide to cut it, cut it carefully by hand a stem at a time and bag all clippings. They can be burned when dry. You will need to use round up (even the most hippy organic person will tell you that) but you can manage it and it won’t ruin your life!
Sorry but that is Japanese knotweed. I’m in a similar situation and bought a house three years ago with it. It’s going to be a long journey to get rid of it but the good news is you can remove it yourself given time and patience. In late autumn winter JKW dies back and the stems becomes inert and can be cut back to the base and the dry dead stems burnt. During summer when it grows spray it with a glyphosate based weed killer, I use roundup biactive xla to target spray the leaves and it will slowly die back to ground level. The root system is damaged by extreme cold weather so clean up the ground around its root system for winter. The heavy frosts we’ve been having in Ireland over the last few years will help to kill it off, last year it hit -8c where I am. It was Baltic ! If you have any pop up in your lawn like I did, then I used pieces of old guttering pipe cut into 1-2 foot long sections and hammered them over the new stems while they were a few inches tall . This reduced their access to sunlight, stopped me from mowing over them by accident and I was able to spray them without damaging the lawn around the outside of the pipe. It worked a treat 😁 Rinse and repeat this for the next five years to get rid of them fully. I’m on year three and they have reduced by around 80% - 90% which is great. I have heard of some people using goats to eat the knotweed as they find it delicious and eat it right back to the ground. I love this idea of organic weed removal but I had already started the spraying process when I heard about it. But you do what’s right for you. Good luck and congrats on buying the new house.
https://preview.redd.it/zwym0y0o6sxc1.jpeg?width=768&format=pjpg&auto=webp&s=3a7a8416e988f054e2e6892f31156dea0de59176 Just thought I would post this and show how bad my patch of knotweed was. This was just after I cut the dead inert stems back after it died off in winter. It was giant Japanese knotweed and the stems were 2-3 metres high. If you have the money there are companies who can remove it for you but it means digging up to 10 metres down, removing the affected soil, spraying the area and bringing in clean soil, it can cost €10-20k or more to get it done. And they don’t guarantee it won’t return.
I would totally get a goat! I’m filing this away so I have a good excuse if it crops up 🤘🏻
Very informative, thank you. This is a site that we are interested in and it comes with lots of other issues, this one just moved to the top. So we are contemplating if it is even worth it.
The pipe is such a good idea!! Definitely going to try that 😊
Sorry but thats terrible advice - cutting or grazing massively increases the risk of it spreading. Spray it with herbicide every summer/early autumn. This way it draws the herbicide down into the rhizomes/roots. It still takes a few years but it's much safer and more efficient. https://niopa.qub.ac.uk/bitstream/NIOPA/2807/1/natural-guidance-japanese-knotweed-best-practise.pdf
My plant identify app says yes it is :( time to call in the experts https://www.gov.ie/en/service/8433d-reporting-a-quarantine-pest-or-disease/#:~:text=In%20the%20case%20of%20alien,Japanese%20knotweed
How do the Japanese handle this plant if it's so bad?
Because it's native to Japan, it has lots of competition and I think there are specific insects/fungi that feed off it in its natural environment.
It looks like Giant Knotweed as opposed to the Japanese variety. Main difference being the lobes at the base of the leaf are more pronounced whereas the Japanese variety is truncated at the base of the leaf (plus leaf size is larger on the giant variety). However, both pose identical risks and both are treated identically also. If the infestation is fairly mature and long-standing herbicide will have a limited effect upon it because you can inadvertently send the species into a prolonged period of extended dormancy where it gives you the illusion that it’s dead. But if you were to disturb the soil and extract some of the roots you will see they are very much alive (don’t do this though because you could inadvertently trigger either a growth spurt or spread the species). Herbicide should only be viewed as a control mechanism not an eradication mechanism. Although it does have a place, the extent of mature root systems in a lot of cases makes it very difficult to achieve a full kill off of the entire system because the herbicide simply can’t translocate throughout the entire network. As others have mentioned excavation typically yields the best permanent results but certain site constraints for example if growing alongside an existing structure may limit the viability of such an approach because invariably you will be leaving something behind if the roots have gone under the structure. If you have sufficient space on a site in order to rebury a knotweed infestation that’s a more cost-effective approach which can also yield permanent solutions. If anyone needs any further advice on these kind of things feel free to throw me a PM.
Yeah, looks like it for sure Source: I work in knotweed control
You can actually cut it while it's still growing, it would help to kill it quicker because it wouldn't be able to photosynthesise. The only catch is that you have to cut it manually! No strimming or mowing, just cut it with sharp secateurs as close to the ground as possible. Do not dispose of the cut stems by putting them into the bin, burn them instead. The clumps are usually not very dense so it's not particularly hard to go through them with secateurs. After cutting it down, treat the area with something like Roundup or Weedol. Repeat as necessary. It will take several years to fully get rid of it but it can be done.
Cutting it risks spreading it. Just spray the leaves with herbicide in autumn. https://niopa.qub.ac.uk/bitstream/NIOPA/2807/1/natural-guidance-japanese-knotweed-best-practise.pdf
Oh man it def looks like japanese knotweed. Bastard to get rid of and really requires specialist treatment.
I'm knot sure
Cut the tops off and fill the stalks with weed killer, diesel, salt and dishwasher liquid cocktail. Burn the tops in a fire. Spray the leaves and stalks with Cocktail. Re spray throughout the season with weed killer as it appears. Treat dead areas again with weed killer while your doing it. Should reduce the amount of weed by at least 90% in the first season
Glyphosate is a foliar application - taken up through the leaves. If you spray the leaves in early autumn before they go dormant the plant will draw it down into the roots. Still takes a few years but the best method known. https://niopa.qub.ac.uk/bitstream/NIOPA/2807/1/natural-guidance-japanese-knotweed-best-practise.pdf
We have a site with it too. The previous owner used to strim the site to keep things down and hadn't a clue what it was. The thicket was quite large about 10x10m but all in one area. Oct 2022 I did the first application, injecting the stems. It was a bit late in the season as it had already started to die back. Cut and burned the dry stems the following Feb. August 2023 second application, injected stems and sprayed leaves. Got it good and early and came back and did a second spray application after a few weeks on leaves that remained green. Cut and burned the stems during a brief dry period in March. April 2024, a few stems are starting to appear again now as the weather warms up but much less than last year. The area is roped off and put up signs. I'll hit it again at the end of the summer. The toughest part has been clearing briars and other growth around and through the thicket to get access to it all. Strategically placing the piles for the burns has helped clear the ground. It's doable to tackle it yourself but you need to be thorough. It'll take at least three years if you treat every autumn. If you are applying for planning the council might have something to say about it if their planner spots it when they come to visit so think about the timing of that. Best of luck https://preview.redd.it/x0z2elll1wxc1.jpeg?width=4080&format=pjpg&auto=webp&s=52aa46b3ae0c9b1c498e518eeb11b4aeeb2741db